Suppressing chaos in damped driven systems by non-harmonic excitations: experimental robustness against potential’s mismatches

The robustness of a chaos-suppressing scenario against potential mismatches is experimentally studied through the universal model of a damped, harmonically driven two-well Duffing oscillator subject to non-harmonic chaos-suppressing excitations. We consider a second order analogous electrical circuit having an extremely simple two-well potential that differs from that of the standard two-well Duffing model, and compare the main theoretical predictions regarding the chaos-suppressing scenario from the latter with experimental results from the former. Our experimental results prove the high robustness of the chaos-suppressing scenario against potential mismatches regardless of the (constant) values of the remaining parameters. Specifically, the predictions of an inverse dependence of the regularization area in the control parameter plane on the impulse of the chaos-suppressing excitation as well as of a minimal effective amplitude of the chaos-suppressing excitation when the impulse transmitted is maximum were experimentally confirmed.Ministerio de Ciencia, Innovación y Universidades (MICIU, Spain) and FEDER funds Project No. PID2019-108508GB-100/AEI/10.13039/501100011033Junta de Extremadura (JEx, Spain) and FEDER funds Project No. GR1808

El lenguaje multimedial : Del Giotto a la holocubierta

Cuando se dicta la primera clase de la asignatura Lenguaje Multimedial se les pregunta a los estudiantes: “¿Qué es multimedia?”. Una de las conclusiones a las que se llega en esa clase es que harán falta los cuatro años de cursada para construir un concepto aproximado sobre la cuestión. La multimedia, como objeto de estudio, aún no está acabadamente definido, por lo que durante esos años deberán hacerse muchas preguntas. Esto sucede, en parte, porque los materiales y las herramientas digitales no parecen haber generado hasta ahora un objeto de estudio preciso dentro del campo del arte. No existe, al presente, un objeto artístico propio que pueda definirse como multimedial. Podríamos decir que estudiar esta carrera en este momento es equivalente a haber estudiado una carrera de cine en los años transcurridos entre el invento de los Lumière y la filmación del El Acorazado Potemkin.Facultad de Bellas Arte

El lenguaje multimedial : Del Giotto a la holocubierta

Cuando se dicta la primera clase de la asignatura Lenguaje Multimedial se les pregunta a los estudiantes: “¿Qué es multimedia?”. Una de las conclusiones a las que se llega en esa clase es que harán falta los cuatro años de cursada para construir un concepto aproximado sobre la cuestión. La multimedia, como objeto de estudio, aún no está acabadamente definido, por lo que durante esos años deberán hacerse muchas preguntas. Esto sucede, en parte, porque los materiales y las herramientas digitales no parecen haber generado hasta ahora un objeto de estudio preciso dentro del campo del arte. No existe, al presente, un objeto artístico propio que pueda definirse como multimedial. Podríamos decir que estudiar esta carrera en este momento es equivalente a haber estudiado una carrera de cine en los años transcurridos entre el invento de los Lumière y la filmación del El Acorazado Potemkin.Facultad de Bellas Arte

El lenguaje multimedial : Del Giotto a la holocubierta

Cuando se dicta la primera clase de la asignatura Lenguaje Multimedial se les pregunta a los estudiantes: “¿Qué es multimedia?”. Una de las conclusiones a las que se llega en esa clase es que harán falta los cuatro años de cursada para construir un concepto aproximado sobre la cuestión. La multimedia, como objeto de estudio, aún no está acabadamente definido, por lo que durante esos años deberán hacerse muchas preguntas. Esto sucede, en parte, porque los materiales y las herramientas digitales no parecen haber generado hasta ahora un objeto de estudio preciso dentro del campo del arte. No existe, al presente, un objeto artístico propio que pueda definirse como multimedial. Podríamos decir que estudiar esta carrera en este momento es equivalente a haber estudiado una carrera de cine en los años transcurridos entre el invento de los Lumière y la filmación del El Acorazado Potemkin.Facultad de Bellas Arte

Impulse-induced localized control of chaos in starlike networks

Locally decreasing the impulse transmitted by periodic pulses is shown to be a reliable method of taming chaos in starlike networks of dissipative nonlinear oscillators, leading to both synchronous periodic states and equilibria (oscillation death). Specifically, the paradigmatic model of damped kicked rotators is studied in which it is assumed that when the rotators are driven synchronously, i.e., all driving pulses transmit the same impulse, the networks display chaotic dynamics. It is found that the taming effect of decreasing the impulse transmitted by the pulses acting on particular nodes strongly depends on their number and degree of connectivity. A theoretical analysis is given explaining the basic physical mechanism as well as the main features of the chaos-control scenario.Ministerio de Economía y Competitividad (MINECO, Spain) Project No. FIS2012-34902 cofinanced by FEDER fundsJunta de Extremadura (JEx, Spain) Project No. GR1514

From nodeless clouds and vortices to gray ring solitons and symmetry-broken states in two-dimensional polariton condensates

We consider the existence, stability and dynamics of the nodeless state and fundamental nonlinear excitations, such as vortices, for a quasi-two-dimensional polariton condensate in the presence of pumping and nonlinear damping. We find a series of interesting features that can be directly contrasted to the case of the typically energy-conserving ultracold alkali-atom Bose–Einstein condensates (BECs). For sizeable parameter ranges, in line with earlier findings, the nodeless state becomes unstable towards the formation of stable nonlinear single or multi-vortex excitations. The potential instability of the single vortex is also examined and is found to possess similar characteristics to those of the nodeless cloud. We also report that, contrary to what is known, e.g., for the atomic BEC case, stable stationary gray ring solitons (that can be thought of as radial forms of Nozaki–Bekki holes) can be found for polariton condensates in suitable parametric regimes. In other regimes, however, these may also suffer symmetry-breaking instabilities. The dynamical, pattern-forming implications of the above instabilities are explored through direct numerical simulations and, in turn, give rise to waveforms with triangular or quadrupolar symmetry.MICINN project FIS2008-0484

Energy localization and transport in two-dimensional electrical lattices

Intrinsic localized modes (ILMs) have been generated and characterized in two-dimensional nonlinear electrical lattices which were driven by a spatially-uniform voltage signal. These ILMs were found to be either stationary or mobile, depending on the details of the lattice unit-cell, as had already been reported in one-dimensional lattices; however, the mo- tion of these ILMs is qualitatively di erent in that it lacks a consistent direction. Furthermore, the hop- ping speed seems to be somewhat reduced in two di- mensions due to an enhanced Peierls-Nabarro (PN)- barrier. We investigate both square and honeycomb lattices composed of 6 x 6 elements. These direct ob- servations were further supported by numerical simu- lations based on realistic models of circuit components. The numerical study moreover allowed for an analysis of ILM dynamics and pattern formation for larger lat- tice sizes

Generation of localized modes in an electrical lattice using subharmonic driving

We show experimentally and numerically that an intrinsic localized mode (ILM) can be stably produced (and experimentally observed) via subharmonic, spatially homogenous driving in the context of a nonlinear electrical lattice. The precise nonlinear spatial response of the system has been seen to depend on the relative location in frequency between the driver frequency, $\omega_d$, and the bottom of the linear dispersion curve, $\omega_0$. If $\omega_d / 2$ lies just below $\omega_0$, then a single ILM can be generated in a 32-node lattice, whereas when $\omega_d / 2$ lies within the dispersion band, a spatially extended waveform resembling a train of ILMs results. To our knowledge, and despite its apparently broad relevance, such an experimental observation of subharmonically driven ILMs has not been previously reported